The purpose of the present study is to evaluate a sample of 1200 persons who participated in the original Evanston-Oak Park fluoridation studies of the 1940's and 1950's to determine the long-range effects of the ingestion of artificially fluoridated water supplies. The subjects will receive comprehensive clinical examinations to assess DMFS, periodontal conditions, occlusal status, root surface caries, and selected behavioral indices such as dental visit behavior, attitudes towards dentistry, preventive dental activities, and fear of dentistry. The significance of this study lies in the fact that the original data from the Evanston-Oak Park studies is now maintained in the Archives of the Research Institute of the American Dental Association Health Foundation and can be retrieved for any comparisons that may be deemed desirable. In addition, this study will constitute one of the few that has looked at the long-range effects of artificial fluoridation using original study participants after some 25 years,